Cleaning sheet, conveying member using the same, and substrate processing equipment cleaning method using them

ABSTRACT

A cleaning sheet has a cleaning layer having a surface resistivity not less than 1×10 13  Ω/□. In a method of manufacturing a conveying member with a cleaning function, for sticking the cleaning sheet, in which the cleaning layer formed of an adhesive that is polymerized/cured by an active energy is provided onto one surface of a base material and an ordinary adhesive layer is provided onto the other surface thereof, onto the conveying member via an ordinary adhesive layer to have a shape larger than the shape of the conveying member and then cutting the cleaning sheet along a shape of the conveying member, wherein a polymerizing/curing reaction of the cleaning layer is carried out after the cleaning sheet is cut out into the shape of the conveying member.

TECHNICAL FIELD

The present invention relates to a sheet for cleaning various devices, acleaning sheet for a substrate processing equipment that is verysusceptive to influences from the foreign matter, for example, amanufacturing system, a test system, etc. for a semiconductor device, aflat panel display, a printed substrate, etc., and a conveying memberusing the same, and a substrate processing equipment cleaning methodusing them.

BACKGROUND ART

Various substrate processing equipments convey the substrate whilephysically contacting the substrate to respective conveying systems. Atthat time, if the foreign matter is stuck to the substrate and theconveying system, subsequent substrates are contaminated sequentially,and thus the equipment must be stopped periodically and subjected to thecleaning process. For this reason, there is the problem such that thereduction in the rate of operation is caused and the great labor isneeded. In order to overcome these problems, the method ofcleaning/removing the foreign matter adhered to the inside of thesubstrate processing equipment by conveying the substrate to which theadhesive substance is adhered (For example, Unexamined Japanese PatentPublication 10-154686), the method of removing the foreign matteradhered to the back surface of the substrate by conveying the plate-likemember (Unexamined Japanese Patent Publication 11-87458), the method ofemploying the dummy wafer charged by the corona charge (UnexaminedJapanese Patent Publication 2000-260671), etc. were proposed.

The method of cleaning/removing the foreign matter adhered to the insideof the substrate processing equipment by conveying the substrate towhich the adhesive substance is adhered is the effective method toovercome the above subjects. However, there is such a possibility thatthe adhesive substance is not released because the adhesive substanceand the equipment contact portion are too strongly adhered not torelease, so that there is such a possibility that the substrate cannotbe surely conveyed. Particularly, if the low pressure sucking mechanismis employed in the chuck table of the table, such possibility is great.Also, the method of removing the foreign matter by conveying theplate-like member can execute the conveyance without hindrance, butthere is the problem that the vital dust removing characteristic isinferior. Also, the method of employing the dummy wafer charged by thecorona charge is the effective method that can also remove the foreignmatter in the neighborhood of the wafer, but the corona generationpotential must be set higher if the surface potential is tried toincrease. Thus, if the cleaning sheet is employed as in the presentinvention, the corona processing conditions are not strongly set becausethe holes are opened depending on the constituent material, and also thesurface potential cannot be increased. Therefore, the surface potentialcan be charged up to only several tens V by the corona method and thusthe suction of the foreign matter is not sufficient yet.

DISCLOSURE OF INVENTION

The present invention has been made in light of such circumstances, andit is an object of the present invention to provide a cleaning sheetthat makes it possible to convey the substrate in the substrateprocessing equipment without fail and also to simply reduce the foreignmatters adhered to the equipment.

In order to achieve the above object, as the result of the earneststudy, it was found that a cleaning sheet or a conveying member can beconveyed in the substrate processing equipment without fail and foreignmatters can be simply and certainly removed by conveying the cleaningsheet or the conveying member having the cleaning sheet such as asubstrate to remove foreign matters away from the interior of asubstrate processing equipment, wherein an adhesive layer as a cleaninglayer has a surface resistivity not less than a specific value, or has arelative dielectric constant or a surface potential not less than aspecific value, or has a surface free energy not less than a specificvalue, to thereby achieve the present invention.

That is, the present invention relates to a cleaning sheet having acleaning layer whose surface resistivity is not less than 1×10¹³ Ω/□.The cleaning sheet may be provided with a base material. The cleaninglayer set forth may be provided on one surface of a base material and anordinary adhesive layer may be provided on another surface thereof. Arelative dielectric constant of the cleaning layer is preferably largerthan 2.0. A surface free energy of the cleaning layer is preferably notless than 30 mJ/m2. A surface potential of the cleaning layer preferablyexceeds 10 kV. The cleaning layer may be formed as an electret by athermal electret method. The above cleaning sheets may be furthermodified from other aspects.

Features and advantages of the invention will be evident from thefollowing detailed description of the exemplary embodiments.

Exemplary Embodiments for Carrying Out the Invention

The cleaning sheet of the present invention has a cleaning layer(including the cleaning layers as modes such as a cleaning sheet singlebody, a laminated sheet, a laminated sheet of the cleaning sheet and abase material, or the like hereinafter) whose surface resistivity is notless than 1×10¹³ Ω/□, preferably not less than 1×10¹⁴ Ω/□. In thepresent invention, since the cleaning layer is formed as close to theinsulator as possible by designing the surface resistivity of thecleaning layer to exceed a specific value, there can be achieved such anadvantage that the foreign matters caused by not only the adhesion butalso the static electricity can be caught and adsorbed. Accordingly, incase the surface resistivity is set below 1×10¹³ Ω/□, thecapture/adsorption effect of the foreign matters caused by such staticis remarkably lowered.

Further, it is desirable that the above cleaning layer should be formedof material whose relative dielectric constant measured under followingconditions is larger than 2.0, preferably not less than 2.1 and morepreferably from 2.1 to 10. In the present invention, since the cleaninglayer is formed close to the high-dielectric material as much aspossible by designing the relative dielectric constant of the cleaninglayer to exceed such specific value, there can be achieved such anadvantage that the foreign matters caused by the static electricity canbe caught and adsorbed.

The relative dielectric constant signifies the magnitude of theelectrical energy stored when the electric field is applied to thematerial by using a ratio to the dielectric constant in a vacuum, andmeasured based on JIS K6911.

The material, the design method, etc. of such cleaning layer is notparticularly limited inasmuch as the relative dielectric constant is setwithin the above range. In the present invention, it is preferable thatthe organic material that does not contain conductive material such asthe additive having the electrically conducting function should beemployed. As particular examples, for example, in addition to thematerial obtained by causing the compound, that has one unsaturateddouble bond or more in the molecule, to contain into thepressure-sensitive adhesive polymer, there may be employed preferablyrubbers, natural resins, synthetic resins such as polyethyleneterephthalate, phenol resin, polyester resin, alkyd resin, epoxy resin,polycarbonate, cellulose nitrate, poly(vinylidene fluoride),polypropylene, polyimide, nylon 6, nylon 66, poly(methyl methacrylate),methyl methacrylate/styrene copolymer, ethylene fluoride/propylenecopolymer, etc.

Also, it is desired that the surface free energy of the cleaning layershould be not less than 30 mJ/m², preferably from 40 to 60 mJ/m². In thepresent invention, the surface free energy of the cleaning layer (solidstate) signifies the surface free energy value of the solid state thatis obtained by measuring contact angles of the water and the methyleneiodide to the surface of the cleaning layer respectively, thensubstituting this measured value and the surface free energy values(already known in the reference) of the contact angle measured liquidsinto a following equation 1 derived from the Young's equation and theextended Fowkes' equation, and then solving two resultant equations as asimultaneous linear equation.

(1+cos θ)γ_(L)=2{square root over ((γ_(s) ^(d)γ_(L) ^(d)))}+2{squareroot over ((γ_(s) ^(P)γ_(L) ^(p)))}  <Equation 1>

where each symbol in the equation is given as follows respectively.

θ: contact angle

γ_(L): surface free energy of the contact angle measured liquid

γ_(L) ^(d): dispersion force component in γ_(L)

γ_(L) ^(P): polar force component in γ_(L)

γ_(s) ^(d): dispersion force component in the surface free energy of thesolid state

γ_(s) ^(P): polar force component in the surface free energy of thesolid state

The cleaning sheet is preferably designed such that the surface of thecleaning layer exhibits a contact angle of not more than 90 degrees,more preferably from 80 to 50 degrees with respect to water. In theinvention, by designing the cleaning layer such that it exhibits asurface free energy and a contact angle with respect to water fallingwithin the range defined above, an effect to cause the cleaning layer toremove the foreign matters stuck to the position to be cleaned can beexerted during conveying of the cleaning sheet or the like.

Also, it is desirable that the modulus of elasticity in tension of thecleaning layer (based on the test method JIS K7127) should be set notlarger than 2000 N/mm², preferably larger than 1 N/mm². If the modulusof elasticity in tension is designed in such range, the cleaning layerdoes not have substantially the tackiness and thus the foreign mattercan be removed not to generate the conveyance trouble.

It is preferable that the surface potential of the cleaning layer is setto exceed 10 kV, normally about 10 to 50 kV. In the present invention,it may be considered that, if the cleaning layer has the surfacepotential in such specific range, the electric field is formed aroundthe cleaning layer to have a strong adsorption force and thus the dustremoving effect can be obtained due to the adsorption force even in thesituation that the cleaning layer does not have substantially thetackiness, as described later.

The method of maintaining such surface potential is not particularlylimited. For example, the method of forming various polymers as theelectret by the thermal electret method, etc. (referred to as “electretformation” hereinafter), the method of suppressing the discharge byselecting the material with the high volume resistivity to reduce acurrent flowing in the material, etc. may be listed.

The material, etc. of such polymer are not limited as far as the polymercan be formed as the electret. For example, the polymers such aspolypropylene, polyethylene terephthalate, polyethylene naphthalate,poly(vinylidene fluoride), vinylidene fluoride, vinylidene trifluoride,polytetrafluoroethylene, etc, the curing pressure-sensitive adhesivecomposition in which the crosslinking reaction and the curing isaccelerated by the active energy source such as the ultraviolet ray, theheat, etc. described later, etc. may be listed.

Also, it is preferable that the cleaning layer of the present inventionshould not have substantially the tackiness. Where “not havesubstantially the tackiness” signifies that, if the essential propertyof the tackiness is assumed as the friction as the resistance againstthe slip, no pressure-sensitive tack representative of the adhesivefunction is present. This pressure-sensitive tack appears if the modulusof elasticity of the adhesive material is in the range up to 1 N/mm² incompliance with the Dahlquist's standard, for example. Accordingly, inthe present invention, if the modulus of elasticity in tension isdesigned in a specific range, i.e., in the range of 1 to 3000 N/mm²,preferably 100 to 2000 N/mm² such that the modulus of elasticity can beincreased larger than 1 N/mm², the foreign matter can be removed not togenerate the conveyance trouble. Where the modulus of elasticity intension is measured based on the test method JIS K7127.

It is preferable that the material whose modulus of elasticity intension can be enhanced by accelerating the crosslinking reaction andthe curing by the active energy source such as the ultraviolet ray, theheat, etc. should be selected as such cleaning layer. Further, it ispreferable that the wettability between the cleaning layer and thecleaned portion in the equipment should be small. If such wettability islarge, there is the possibility that the cleaning sheet is stuck tightlyto the cleaned portion in conveying to cause the conveyance trouble.Also, a thickness of the cleaning layer is not particularly limited, butnormally the thickness is set to about 5 to 100 μm.

The material, etc. of such cleaning layer is not particularly limitedinasmuch as the surface resistivity is within the above range. But theadhesive layer that does not contain the conductive material such as theadditive having the conducting function is preferable. In addition, thematerial that can be cured by the active energy source such as theultraviolet ray, the heat, etc. to change the molecular structure intothree-dimensional net and to lower the adhesive force is preferable assuch adhesive layer. For example, the 180° releasing adhesive force forthe silicon wafer (mirror surface) is not more than 0.20 N/10 mm,preferably about 0.010 to 0.10 N/10 mm. If this adhesive force exceeds0.20 N/10 mm, there is the chance that the cleaning layer is adhered tothe cleaned portion in the equipment in conveying to cause theconveyance trouble.

The material, etc. of such cleaning layer is not particularly limitedinasmuch as the surface free energy is below the above specific value.But the adhesive layer that can be cured and crosslinked by the activeenergy source such as the ultraviolet ray, the heat, etc. to change themolecular structure into three-dimensional net and to lower or lose theadhesive force is preferable. If such adhesive layer is employed, thecleaning layer is never strongly adhered to the cleaned portion duringthe conveying and thus the cleaning layer can be conveyed without fail.

As the particular examples of such cleaning layer, the material obtainedby causing at least the compound, that has one unsaturated double bondor more in the molecule, and the polymerization initiator to containinto the pressure-sensitive adhesive polymer, and the material whoseadhesiveness is lost by generating the polymerization and curingreaction by applying the active energy may be listed. As suchpressure-sensitive adhesive polymer, for example, there may be listedthe acrylic polymer that contains (metha)acrylic acid and/or (metha)acrylic ester selected from acrylic acid, acrylic ester, methacrylicacid, and ester methacrylate as the main monomer. In synthesizing thisacrylic polymer, the compound that that has two unsaturated double bondsor more in the molecule may be employed as the copolymerization monomer,otherwise this polymer itself may be caused to take part in thepolymerization and curing reaction by the active energy if theunsaturated double bonds are introduced into the molecules of theacrylic polymer by chemically bonding the compound having theunsaturated double bonds to the molecules of the synthesized acrylicpolymer via the reaction between the functional groups.

Here, the compound that is nonvolatile and is the low molecular weightsubstance having the weight-average molecular weight of less than 10000is preferable as the compound that has one unsaturated double bond ormore in the molecule (referred to as “polymerized unsaturated compound”hereinafter). It is preferable particularly that the compound that hasthe molecular weight of less than 5000 should be employed to execute thechange of the adhesive layer into the three-dimensional net effectivelyin curing.

Here, the compound that is nonvolatile and is the low molecular weightsubstance having the weight-average molecular weight of not more than10000 is preferable as the polymerized unsaturated compound. It ispreferable particularly that the compound that has the molecular weightof not more than 5000 should be employed to execute the change of thecleaning layer into the three-dimensional net effectively in curing. Assuch polymerized compound, for example, there may be listed phenoxypolyethylene glycol (metha) acrylate, ε-caprolactone (metha)acrylate,polyethylene glycol di(metha)acrylate, polypropylene glycoldi(metha)acrylate, trimethylpropane tri(metha)acrylate,dipentaerythritol hexa (metha)acrylate, urethane (metha)acrylate,epoxy(metha)acrylate, oligoester (metha)acrylate, etc. One type or twotypes of them may be employed.

Also, the polymerization initiator added to the cleaning layer is notparticularly limited and the publicly known initiator can be employed.For example, there may be listed the thermal polymerization initiatorsuch as benzoyl peroxide, azobisisobutyronitrile, etc. if the heat isemployed as the active energy source, otherwise there may be listed thephotopolymerization initiator such as benzoyl, benzoin ethyl ester,dibenzyl, isopropyl benzoin ester, benzophenone, Michler's ketonechlorothioxanthone, dodecylthioxanthone, dimethylthioxanthone,acetophenone diethyl ketal, benzyldimethyl ketal,α-hydroxycyclohexylphenyl ketone, 2-hydroxydimethylphenyl propane,2,2-dimethoxy-2-phenylactophenone, etc. if the light is employed as theactive energy source.

The base material used when such cleaning layer is provided to the basematerial is not particularly limited. But, for example, there may belisted the plastic film such as polyethylene, polyethyleneterephthalate, acetylcellulose, polycarbonate, polypropylene, polyamide,polyimide, polycarbodiimide, etc. The thickness is normally about 10 to100 μm.

Further, the present invention provides the cleaning sheet in which thecleaning layer is provided on the one side of the base material and theordinary adhesive layer is provided on the other side thereof. Thematerial, etc. of this ordinary adhesive layer are not particularlylimited as far as the adhesive layer can satisfy the adhering function,and the ordinary adhesive (e.g., acrylic adhesive, rubber adhesive,etc.) may be employed.

According to such structure, the cleaning sheet is stuck onto theconveying member such as various substrates, other tape sheet, etc. viathe ordinary adhesive layer and then conveyed as the conveying memberwith the cleaning function in the equipment to come into contact withthe cleaned portion, whereby the cleaning is carried out. Also, if thesubstrate is peeled off from such adhesive layer after the cleaning toreuse the conveying member such as the above substrate, the adhesiveforce of such ordinary adhesive layer is not particularly limited if itis in the range to enable the peeling-off again. However, it ispreferable that the 180° releasing adhesive force for the silicon wafer(mirror surface) should be less than 0.01 to 0.98 N/10 mm, particularlyabout 0.01 to 0.5 N/10 mm since the cleaning sheet is not peeled offduring the conveying but can be easily peeled off again after thecleaning.

The conveying member to which the cleaning sheet is stuck is notparticularly limited, but the substrate for the flat panel display suchas the semiconductor wafer, LCD, PDP, etc., the substrate for thecompact disk, the MR head, and others, for example, may be listed.

Also, the present invention provides a member for cleaning variousconduction testers and a conduction tester cleaning method using this,for example, a cleaning member and a cleaning method for a conductiontester such as the semiconductor device, the printed substrate, etc.,that is very susceptive to influences from the foreign matter.

Various conduction testers employed in the semiconductor manufacturingtests the electric conduction by bringing the contact point on theconduction tester side (the contact pin of the IC socket, etc.) intocontact with the terminal on the product side (the semiconductorterminal, etc.). At that time, when the contact of the IC terminal andthe contact pin is repeated by the test that is carried out repeatedly,the contact pin scrapes off the material (aluminum, solder, etc.) on theIC terminal side, then the foreign matter is transferred and adhered tothe contact pin side, and then such adhered aluminum, solder, etc. areoxidized to cause the defective insulation. In the worst case, theconduction rate in the test is degraded. Therefore, in order to removethe foreign matter adhered to these contact pins, the foreign matter onthe contact pins is removed by using the member obtained by coating thealumina fine-grains on the polyethylene terephthalate film, or themember obtained by mixing the abrasive grains into the rubber resin suchas silicon (referred to as a contact pin cleaner hereinafter). However,in recent years, any countermeasure against the removal of the foreignmatter on the chuck table is required with the reduction in thicknessand the increase in length of the wafer in the semiconductormanufacturing steps since the wafer is broken due to the foreign matteron the test table (chuck table), the chucking error is generated, andothers. For this reason, in order to remove the foreign matter on thechuck table, the necessity to stop periodically the equipment and toclean the table is generated. Therefore, there are problems such thatthe reduction in the rate of operation is caused and the huge labor isneeded.

In light of such circumstance, the present invention has an object toprovide a cleaning member and a cleaning method capable of cleaningcontact pins of the conduction tester and reducing simply the foreignmatters adhered to a chuck table, a conveying arm, etc.

In order to achieve the above object, as the result of the earneststudy, the inventors of the present invention have found out that, ifthe cleaning member in which the cleaning layer for removing the foreignmatter adhered onto the contacted surface (the chuck table, etc.) of theequipment, with which the contact pin cleaner comes into contact, isprovided to one side of the member for removing the foreign matteradhered to the conduction testing pin of the conduction tester (referredto as a contact pin cleaner hereinafter) is conveyed, the cleaning ofthe contact pin and the removal of the foreign matter adhered to thechuck table, etc. in the test equipment can be performed simultaneously,and also, if the coefficient of friction of the cleaning layer is set toexceed a specific value, the cleaning layer can be conveyed in the testequipment without fail and the foreign matter can be reduced simply, andthus reach the completion of the present invention.

That is, the present invention provides a cleaning member which is thecleaning member for the conduction testing equipment and in which thecleaning sheet for removing the foreign matter adhered onto thecontacted surface of the equipment, with which the contact pin cleanercomes into contact, is provided to one surface of the member forremoving the foreign matter adhered to the conduction testing contactpin of the equipment (referred to as the contact pin cleanerhereinafter).

Also, the present invention provides a cleaning member which is thecleaning member for the conduction testing equipment and in which amember for removing the foreign matter adhered onto the conductiontesting contact pin of the equipment is provided to one surface of theconveying member (referred to as the contact pin cleaner hereinafter),and the cleaning sheet for removing the foreign matter adhered to thecontacted surface of the equipment, with which the contact pin cleanercomes into contact, is provided to the other surface.

The cleaning layer of the cleaning member of the present invention isnot particularly limited if it can be conveyed surely in the testingequipment and it can reduce simply the foreign matter. But it isdesirable from points of the dust removing characteristic and theconveying characteristic that the coefficient of friction should be notless than 1.0, preferably 1.2 to 1.8. There is the possibility that thecleaning layer cannot surely stick to the foreign matter on the chucktable if the coefficient of friction is smaller than 1.0, whereas thereis the possibility that the conveying failure is caused if thecoefficient of friction is too large. In the present invention, thecoefficient of friction (μ) of the cleaning layer is calculated bymeasuring the frictional resistance force (F), that is generated whenthe stainless steel plate (50 mm×50 mm flat plate) is slid with respectto a surface of the cleaning layer, by virtue of the universal tensiontester and then substituting this frictional resistance force and thevertical load (W) applied to the steel plate at that time into afollowing equation 2. Where this coefficient of friction signifies thecoefficient of dynamic friction herein.

 μ=F/W  <Equation 2>

Where each symbol in the equation is given as follows respectively.

μ: coefficient of dynamic friction

F: frictional resistance force [N]

W: vertical load [N] applied to the steel plate

Also, it is desirable that the modulus of elasticity in tension of thecleaning layer should be set to not more than 2000 N/mm², preferablymore than 1 N/mm². There is the possibility that the cleaning layercannot surely stick to the foreign matter on the chuck table if themodulus of elasticity in tension exceeds 2000 N/mm², whereas there isthe possibility that the conveying failure is caused if the modulus ofelasticity in tension is below 1 N/mm². In the present invention, if thecoefficient of friction and the modulus of elasticity in tension of thecleaning layer are set in such specific ranges, there can be achievedthe advantage that the cleaning layer does not substantially have thetackiness at the time when the cleaning sheet, etc. are conveyed andthus the cleaning layer can be conveyed without fail not to stronglyadhere to the cleaned portion.

The material, the shape, etc. of the contact pin cleaner employed in thepresent invention are not particularly limited, and they may be utilizedwidely. For example, the plastic film such as polyethylene, polyethyleneterephthalate, acetylcellulose, polycarbonate, polypropylene, polyamide,polyimide, polycarbodiimide, etc., the rubber resin such as the silicon,the material obtained by coating the abrasive grain such as aluminafine-grain, silicon carbide, chromium oxide, etc. on the base material(backing) such as nonwoven fabric, etc. are employed, but the materialis not limited to the above. Similarly, the shape may be employedappropriately according to the shape of the socket or the IC, that is tobe cleaned, such as the silicon wafer shape, the IC chip shape, etc. andthe type of the equipment.

According to such configuration, the cleaning sheet is stuck onto thenon-cleaned side of the cleaning contact pin cleaner for the contact pinor the conveying member such as various substrates, etc. via theordinary adhesive layer, and then conveyed as the conveying member withthe cleaning function in the equipment to come into contact with thechuck table, etc., whereby the cleaning is carried out.

The conveying member to which the cleaning layer is provided is notparticularly limited. For example, the substrate for the flat paneldisplay such as the semiconductor wafer, LCD, PDP, etc., the substratefor the compact disk, the MR head, the plastic film such aspolyethylene, polyethylene terephthalate, acetylcellulose,polycarbonate, polypropylene, polyamide, polyimide, polycarbodiimide,etc., for example, may be listed.

The present invention provides a method of manufacturing the conveyingmember with the cleaning function for various substrate processingequipments, for example, a method of manufacturing the conveying memberwith the cleaning function for the substrate processing equipment suchas the manufacturing equipment, the inspection equipment, etc. of thesemiconductor device, the flat panel display, the printed substrate,etc., that are very sensitive to the foreign matter.

As for the method of manufacturing the conveying member with thecleaning function (referred to as a cleaning member hereinafter), forexample, in the case that the cleaning member is manufactured bysticking the cleaning sheet onto the conveying member such as thesubstrate, etc., if the cleaning sheet that is larger than the shape ofthe member is stuck to the member and then the cleaning sheet is cutalong the shape of the member (this method is referred to as a directcutting method hereinafter), the problem that is caused since cuttingscobs are generated from the cleaning layer, etc. in cutting the sheetand then adhered to the cleaning member and the equipment. Also, in casethe cleaning member is manufactured by sticking the label cleaningsheet, that is processed previously into the shape of the member, to theconveying member, the generation of the cutting scobs in working thelabel can be suppressed rather than the direct cutting method. But thecutting of the label sheet must be performed previously to increase theoperation steps, and thus the fabrication of the cleaning member becomestroublesome to thus degrade the workability.

In light of such circumstance, the present invention has an object toprovide a method of manufacturing a cleaning member that can be conveyedin the substrate processing equipment without fail, and can removesimply and surely the adhered foreign matter, and also does not generatethe cutting scobs in cutting the sheet by the direct cutting method.

In order to achieve the above object, as the result of the earneststudy, the inventors of the present invention have found out that, ifthe cleaning layer is formed of the adhesive that is polymerized/curedby the active energy when the cleaning member is manufactured by thedirect cutting method upon manufacturing the cleaning member by stickingthe cleaning sheet onto the conveying member such as the substrate, etc.and if the polymerizing/curing reaction of the cleaning layer is carriedout after the cleaning sheet is cut out into the shape of the conveyingmember, the cleaning member capable of releasing simply the foreignmatter without fail can be manufactured without generation of the aboveproblem, and thus reach the completion of the present invention.

That is, the present invention also provides a method of manufacturing aconveying member with a cleaning function, for sticking the cleaningsheet, in which the cleaning layer formed of the adhesive that ispolymerized/cured by the active energy is provided onto one surface ofthe base material and the ordinary adhesive layer is provided onto theother surface thereof, onto the conveying member via the ordinaryadhesive layer to have a shape larger than the shape of the conveyingmember and then cutting the cleaning sheet along the shape of theconveying member, wherein the polymerizing/curing reaction of thecleaning layer is carried out after the cleaning sheet is cut into theshape of the conveying member.

In the method of manufacturing the conveying member of the presentinvention, the cleaning layer must be formed of the adhesive that ispolymerized/cured by the active energy and the polymerizing/curingreaction of the cleaning layer must be carried out after the cleaningsheet is cut. This is because, if the polymerizing/curing reaction ofthe cleaning layer is carried out prior to the cutting of the cleaningsheet, the cleaning layer has the high modulus of elasticity because ofthe crosslinking reaction and also a large amount of cutting scobs aregenerated in cutting and adhered to the cleaning member and theequipment. In order not to generate the cutting scobs from the cleaninglayer in cutting the sheet, it is desired that the modulus of elasticityin tension of the cleaning layer (test method JIS K7127) should be notmore than 1 N/mm², preferably not more than 0.1 N/mm². The generation ofthe cutting scobs from the cleaning layer in cutting the sheet can besuppressed by setting the modulus of elasticity in tension lower thansuch specific value, and thus the cleaning member to which the cuttingscobs are not adhered can be manufactured by the direct cutting method.Also, if the adhesive that is polymerized/cured is employed as thecleaning layer, the adhesiveness is lost substantially from the cleaninglayer by polymerizing/curing the cleaning layer after the cutting of thesheet. Thus, there can be obtained the advantage that the cleaningmember that never strongly comes into contact with the contact portionof the equipment in conveying the cleaning member and can be conveyedsurely can be provided.

In the present invention, it is desirable that, since the crosslinkingreaction and the curing are accelerated by the above active energy, themodulus of elasticity in tension of such cleaning sheet after thecutting of the sheet should be not less than 10 N/mm², preferably 10 to2000 N/mm². The performance for removing the foreign matter adhered tothe conveying system is lowered if this modulus of elasticity in tensionis in excess of 2000 N/mm², whereas there is the possibility that thecleaning layer is adhered to the cleaned portion in the equipment inconveying to cause the conveying trouble if the modulus of elasticity intension is smaller than 10 N/mm².

In manufacturing the cleaning member according to the present invention,there is employed the cleaning sheet in which the cleaning layer formedof the adhesive that is polymerized/cured by the active energy isprovided onto one surface of the base material while the ordinaryadhesive layer is provided onto the other surface thereof.

The present invention will be explained based on examples hereinafter,but the present invention is not limited to these examples. Hereinafter,the term “parts” means parts by weight.

EXAMPLE 1

The ultraviolet curing adhesive solution was formed by mixing uniformlythe polyethylene glycol dimethacrylate 50 parts, the urethane acrylate50 parts, the benzyldimethylketal 3 parts, and thediphenylmethanediisocyanate 3 parts into the acrylic polymer(weight-average molecular weight 700000) 100 parts obtained from themonomer mixed solution consisting of the acrylic acid-2-ethyl hexyl 75parts, the methyl acrylate 20 parts, and the acrylic acid 5 parts.

In contrast, the ordinary adhesive layer was provided by coating theadhesive solution, that was obtained in the same way except that thebenzyldimethylketal was removed from the above adhesive, on one surfaceof the polyester base material film, that had a width of 250 mm and athickness of 25 μm, to have a thickness of 10 μm after the drying,whereby the polyester releasing film of 38 μm thickness was pasted onthe surface. The adhesive layer is provided as the cleaning layer bycoating the above ultraviolet curing adhesive solution on another sideof the base material film to have a dried thickness of 40 μm, wherebythe similar releasing film was pasted on the surface.

The cleaning sheet of the present invention was obtained by irradiatingthe ultraviolet rays having a central wavelength 365 nm by an integratedquantity of light 1000 mJ/cm² onto this sheet. When the surfaceresistivity was measured via the cleaning layer by the surfaceresistivity measuring device (type MCP-UP450 manufactured by MitsubishiChemical Industries Ltd.) at the temperature of 23° C. and the humidityof 60% after the releasing film on the cleaning layer side of thiscleaning sheet was peeled off, it was impossible to measure the surfaceresistivity if such surface resistivity exceeds 9.99×10¹³ Ω/□.

Also, when the adhesive layer on the cleaning layer side was pasted ontothe mirror surface of the silicon wafer to have a width of 10 mm andthen the 180° releasing adhesive force for the silicon wafer wasmeasured based on JIS Z0237, 0.078 N/10 mm was obtained.

The conveying cleaning wafer with the cleaning function was fabricatedby peeling off the releasing film on the ordinary adhesive layer side ofthis cleaning sheet and then pasting this film onto a back surface(mirror surface) of the 8-inch silicon wafer by the hand roller.

In contrast, when two wafer stages of the substrate processing equipmentwere removed and then the number of the foreign matter having a size ofnot less than 0.3 μm was counted by the laser foreign-matter measuringdevice, 25000 foreign matters were counted in one area of the 8-inchsilicon wafer size and 22000 foreign matters were counted in anotherarea thereof.

Then, when the releasing film on the cleaning layer side of theresultant conveying cleaning wafer was peeled off and then the wafer wasconveyed into the substrate processing equipment that has the waferstage to which the 25000 foreign matters were adhered, the wafer couldbe conveyed without trouble. Then, when the wafer stage was removed andthe number of the foreign matter having a size of more than 0.3 μm wascounted by the laser foreign-matter measuring device, 6200 foreignmatters were counted in the 8-inch silicon wafer size. Thus, the foreignmatters adhered before the cleaning could be removed in number by ¾ ormore.

Comparative Example 1

When the cleaning sheet was fabricated in the same way as Example 1other than that the additive (product name V-SQ-S6 manufactured byMitsubishi Chemical Industries Ltd.) 5 parts that have the 4-th classammonium salt having the conducting function in the side chain was addedinto the adhesive layer of the cleaning layer and then the surfaceresistivity of the cleaning layer was measured in the same way, 5.5×10¹¹Ω/□ was obtained. Also, when the adhesive force of the adhesive layer ofthe cleaning layer to the silicon wafer was measured, 0.33 N/10 mm wasobtained.

When the conveying cleaning wafer fabricated in the same way as Example1 from this cleaning sheet is conveyed into the substrate processingequipment that has the wafer stage to which the 22000 foreign mattersare adhered, the wafer can be conveyed without trouble. Then, when thewafer stage was removed and the number of the foreign matter having asize of not less than 0.3 μm was counted by the laser foreign-mattermeasuring device, 20000 foreign matters were counted in the 8-inchsilicon wafer size. Thus, the foreign matters adhered before thecleaning could be removed in number merely by about {fraction (1/11)}.

EXAMPLE 2

The ultraviolet curing adhesive solution was formed by mixing uniformlythe dipentaerythritolhexacrylate (product name UV1700B manufactured byThe Nippon Synthetic Chemical Industry, Co., Ltd.) 150 parts, thebenzyldimethylketanol 5 parts, and the diphenylmethanediisocyanate 3parts into the acrylic polymer (weight-average molecular weight 700000)100 parts obtained from the monomer mixed solution consisting of theacrylic acid-2-ethyl hexyl 75 parts, the methyl acrylate 20 parts, andthe acrylic acid 5 parts.

In contrast, the adhesive solution was obtained in the same way as aboveexcept that the benzyldimethylketanol is removed from the aboveadhesive.

The ordinary adhesive layer was provided by coating the above adhesivesolution on one surface of the polyethylene terephthalate, that had awidth of 250 mm and a thickness of 25 μm, as the base material to have adried thickness of 10 μm, whereby the polyester releasing film of 38 μmthickness was pasted on the surface. Also, the adhesive layer wasprovided as the cleaning layer by coating the above ultraviolet curingadhesive solution on the other side of the base material to have a driedthickness of 20 μm, whereby the similar releasing film was pasted on thesurface.

The cleaning sheet A of the present invention was obtained byirradiating the ultraviolet rays having a central wavelength 365 nm byan integrated quantity of light 2000 mJ/cm² onto this sheet. When therelative dielectric constant of the cleaning layer of this cleaningsheet was measured by the LCR meter (Type 4284A manufactured by HewlettPackard Co., Ltd.) at 1 MHz, 2.8 was obtained.

EXAMPLE 3

The cleaning sheet B of the present invention was obtained by providingthe ordinary adhesive layer in the same way as Example 2 on one surfaceof the polyethylene terephthalate film (width 250 mm, thickness 25 μm)whose relative dielectric constant is 3.2 and then pasting the similarreleasing film on the surface.

The conveying cleaning wafers A and B with the cleaning function werefabricated by peeling off the releasing film on the ordinary adhesivelayer side of the resultant cleaning sheets A and B and then pasting thefilm on the back surface (mirror surface) of the 8-inch silicon wafer bythe hand roller.

In contrast, when the foreign matters having a size of more than 0.2 μmon the mirror surfaces of three sheets of new 8-inch silicon wafers werecounted by the laser foreign-matter measuring device, 11 foreign matterswere counted on the first sheet, 10 foreign matters were counted on thesecond sheet, and 8 foreign matters were counted on the third sheet.When these wafers were conveyed into the substrate processing equipmentthat has separate electrostatic adsorbing mechanisms while directing themirror surface downward and then the mirror surfaces were measured bythe laser foreign-matter measuring equipment, 32004, 25632, and 27484foreign matters were counted in the area of the 8-inch wafer sizerespectively.

Then, when the releasing films on the cleaning layer side of theresultant conveying cleaning wafers A, B were peeled off and then thewafers were conveyed into the substrate processing equipment that hasthe wafer stages to which the above 32004 and 27484 foreign matters wereadhered respectively, the wafer could be conveyed without trouble. Then,the new 8-inch silicon wafers to which 10 and 13 foreign matters havinga size of not less than 0.2 μm were conveyed while directing the mirrorsurface downward and then the foreign matters having the size of notless than 0.2 μm were counted by the laser foreign-matter measuringdevice. This process was carried out five times, and the results areshown in Table 1.

Comparative Example 3

The cleaning sheet C was obtained in the same way as Example 3 otherthan that the polytetrafluoroethylene whose relative dielectric constantis 2.0 was used as the film in Example 3.

The conveying cleaning wafer C that was fabricated in the same way asExample 3 from the cleaning sheet was conveyed into the substrateprocessing equipment that has the wafer stage to which the 25632 foreignmatters were adhered. This operation was repeated five times likeExample 3, and the results are shown in Table 1.

TABLE 1 Foreign-matter rejection ratio 1 sheet 2 sheets 3 sheets 4sheets 5 sheets conveyed conveyed conveyed conveyed conveyed Example 284% 90% 96% 96% 96% Wafer A Example 3 69% 72% 73% 73% 75% Wafer BComparative 19% 20% 19% 21% 21% Example 3 Wafer C

EXAMPLE 4

The ultraviolet curing adhesive solution was prepared by mixinguniformly the polyethylene glycol 200 dimethacrylate (product nameNKester4G manufactured by Shin-Nakamura Chemical Co., Ltd.) 50 parts,the urethane acrylate (product name U-N-01 manufactured by Shin-NakamuraChemical Co., Ltd.) 50 parts, and the polyisocyanate compound (productname Colonate L manufactured by Nippon Polyurethane Industry Co., Ltd.)3 parts, and the benzyldimethylketal (product name Illugacure 651manufactured by Chiba-Speciality Chemicals Co., Ltd.) 3 parts as thephotopolymerization initiator into the acrylic polymer (weight-averagemolecular weight 700000) 100 parts obtained from the monomer mixedsolution consisting of the acrylic acid-2-ethyl hexyl 75 parts, themethyl acrylate 20 parts, and the acrylic acid 5 parts.

In contrast, the ordinary adhesive layer was provided by coating theadhesive solution, that was obtained in the same way except that thebenzyldimethylketal as the photopolymerization initiator was removedfrom the above adhesive solution A, on one surface of the polyester basematerial film, that had a width of 250 mm and a thickness of 25 μm, tohave the dried thickness of 10 μm, whereby the polyester releasing filmof 38 μm thickness was pasted on the surface. Then, the adhesive layeras the cleaning layer was provided by coating the above ultravioletcuring adhesive solution A on the other side of the base material filmto have the dried thickness of 10 μm, whereby the similar releasing filmwas pasted on the surface.

The cleaning sheet of the present invention was obtained by irradiatingthe ultraviolet rays having a central wavelength 365 nm until anintegrated quantity of light 1000 mJ/cm² onto this sheet. Then, thereleasing film on the cleaning layer side of this cleaning sheet waspeeled off. The measured surface free energy of the cleaning layer was40.1 mJ/m², and the measured contact angle with respect to water was78.2 degree.

The conveying cleaning wafer with the cleaning function was fabricatedby peeling off the releasing film on the ordinary adhesive layer side ofthis cleaning sheet and then pasting this film onto a back surface(mirror surface) of the 8-inch silicon wafer by the hand roller.

In contrast, when two wafer stages of the substrate processing equipmentwere removed and then the number of the foreign matter having a size ofnot less than 0.3 μm was counted by the laser foreign-matter measuringdevice, 25000 foreign matters were counted in one area of the 8-inchsilicon wafer size and 23000 foreign matters were counted in anotherarea thereof.

Then, when the releasing film on the cleaning layer side of theresultant conveying cleaning wafer was peeled off and then the wafer wasconveyed into the substrate processing equipment that has the waferstage to which the 25000 foreign matters are adhered, the wafer could beconveyed without trouble. Then, when the wafer stage was removed and thenumber of the foreign matter having a size of more than 0.3 μm wascounted by the laser foreign-matter measuring device, 4800 foreignmatters were counted in the 8-inch silicon wafer size. Thus, the foreignmatters adhered before the cleaning could be removed in number by ⅘ ormore.

Comparative Example 4

A cleaning sheet was formed in the same manner as the Example 4 exceptfor using an ultraviolet curing adhesive solution B prepared by mixinguniformly the dipentaerythtorolhexaacrylate (product name UV1700Bmanufactured by The Nippon Synthetic Chemical Industry, Co., Ltd.) 100parts, and the polyisocyanate compound (product name Colonate Lmanufactured by Nippon Polyurethane Industry Co., Ltd.) 3 parts, and thebenzyldimethylketal (product name Illugacure 651 manufactured byChiba-Speciality Chemicals Co., Ltd.) 10 parts as thephotopolymerization initiator into the acrylic polymer (weight-averagemolecular weight 2800000) 100 parts obtained from the monomer mixedsolution consisting of the acrylic acid-2-ethyl hexyl 30 parts, themethyl acrylate 70 parts, and the acrylic acid 10 parts. The measuredsurface free energy of the cleaning layer was 24.6 mJ/m², and themeasured contact angle with respect to water was 82.3 degree.

Then, a conveying cleaning wafer obtained by the same manner as in theExample 4 was conveyed into the substrate processing equipment that hasthe wafer stage to which the 23000 foreign matters are adhered, thewafer could be conveyed without trouble. Then, when the wafer stage wasremoved and the number of the foreign matter having a size of more than0.3 μm was counted by the laser foreign-matter measuring device, 20000foreign matters were counted in the 8-inch silicon wafer size. Thus, theforeign matters adhered before the cleaning could be removed only innumber by about ⅛.

EXAMPLE 5

The ultraviolet curing adhesive solution was formed by mixing uniformlythe dipentaerythtorolhexaacrylate (product name UV1700B manufactured byThe Nippon Synthetic Chemical Industry, Co., Ltd.) 150 parts, thebenzyldimethylketanol 5 parts, and the diphenylmethanediisocyanate 3parts into the acrylic polymer (weight-average molecular weight 700000)100 parts obtained from the monomer mixed solution consisting of theacrylic acid-2-ethyl hexyl 75 parts, the methyl acrylate 20 parts, theacrylic acid 5 parts.

In contrast, the ordinary adhesive layer was provided by coating theadhesive solution, that is obtained in the same way except that thebenzyldimethylketal was removed from the above adhesive, on one surfaceof the polyethylene terephthalate base material film, that has a widthof 250 mm, a thickness of 70 μm, and a tensile strength of 250 Mpa tohave the dried thickness of 10 μm, whereby the polyester releasing filmof 38 μm thickness was pasted on the surface. The cleaning layer wasprovided by coating the above ultraviolet curing adhesive solution onthe other side of the base material film to have the dried thickness of40 μm, whereby the similar releasing film was pasted on the surface.

The ultraviolet rays having a central wavelength 365 nm was irradiatedby an integrated quantity of light 2000 mJ/cm² onto this sheet from thecleaning layer side, then the releasing film on the cleaning layer sideis peeled off, then the cleaning layer was inserted between theelectrodes in the atmosphere by employing the thermal electret method,then the voltage of 20 kV is applied at the temperature of 100° C., thenthe cleaning layer was cooled down to 40° C. while applying the voltageas it is, and then the application of the voltage was ended to form thecleaning layer as the electret. When the surface potential was measuredat an electrode-sample interval of 20 mm by the static electricitymeasuring device (Model FMX002 manufactured by Simco Japan Co. Ltd.)under conditions of 25° C. and 55% RH, 15 kV was obtained. Also, thesurface of the cleaning layer did not substantially have the tackiness,and the modulus of elasticity in tension of the cleaning layer after theultraviolet curing was 1980 N/mm².

The conveying cleaning wafer with the cleaning function was fabricatedby peeling off the releasing film on the ordinary adhesive layer side ofthe resultant cleaning sheet and then pasting the film on the backsurface (mirror surface) of the 8-inch silicon wafer by the hand roller.

In contrast, when the foreign matters having a size of more than 0.2 μmon the mirror surfaces of two sheets of new 8-inch silicon wafers arecounted by the laser foreign-matter measuring device, 11 foreign matterswere counted on the first sheet, and 10 foreign matters were counted onthe second sheet. When these wafers were conveyed into the substrateprocessing equipment that has separate electrostatic adsorbingmechanisms while directing the mirror surface downward and then themirror surfaces are measured by the laser foreign-matter measuringequipment, 32004 and 25632 foreign matters were counted in the area ofthe 8-inch wafer size respectively.

Then, when the releasing film on the cleaning layer side of theresultant conveying cleaning wafer was peeled off and then the wafer isconveyed into the substrate processing equipment that has the waferstages to which the above 32004 and 27484 foreign matters were adheredrespectively, the wafer can be conveyed without trouble. Then, the new8-inch silicon wafers to which the 10 foreign matters having the size ofmore than 0.2 μm were conveyed while directing the mirror surfacedownward and then the foreign matters having the size of more than 0.2μm were counted by the laser foreign-matter measuring device. Thisprocess was repeated five times, and the results are shown in Table 2.

Comparative Example 5

When the cleaning sheet was obtained in the same way as Example 5 otherthan that the additive (product name V-SQ-S6 manufactured by MitsubishiChemical Industries Ltd.) 20 parts that have the 4-th class ammoniumsalt having the conducting function in the side chain was added into thecleaning layer in the cleaning sheet in Example 5. The surface potentialof the cleaning layer measured after the irradiation of the ultravioletrays like Example 5 was 0.04 kV, and the modulus of elasticity intension was 1720 N/mm².

The conveying cleaning wafer that was fabricated in the same way asExample 5 from the cleaning sheet was carried out five times into thesubstrate processing equipment that has the wafer stage to which the25632 foreign matters were adhered, like Example 5. The results areshown in Table 2.

TABLE 2 Foreign-matter rejection ratio 1 sheet 2 sheets 3 sheets 4sheets 5 sheets conveyed conveyed conveyed conveyed conveyed Example 584% 90% 96% 96% 96% Comparative Example 5 20% 23% 23% 30% 31%

EXAMPLE 6

The ultraviolet curing adhesive solution was prepared by mixinguniformly the polyethylene glycol 200 dimethacrylate (product nameNKester4G manufactured by Shin-Nakamura Chemical Co., Ltd.) 50 parts,the urethane acrylate (product name U-N-01 manufactured by Shin-NakamuraChemical Co., Ltd.) 50 parts, and the polyisocyanate compound (productname Colonate L manufactured by Nippon Polyurethane Industry Co., Ltd.)3 parts, and the benzyldimethylketal (product name Illugacure 651manufactured by Chiba-Speciality Chemicals Co., Ltd.) 3 parts as thephotopolymerization initiator into the acrylic polymer (weight-averagemolecular weight 700000) 100 parts obtained from the monomer mixedsolution consisting of the acrylic acid-2-ethyl hexyl 75 parts, themethyl acrylate 20 parts, and the acrylic acid 5 parts.

In contrast, the ordinary adhesive layer was provided by coating theadhesive solution, that was obtained in the same way except that thebenzyldimethylketal as the photopolymerization initiator was removedfrom the above adhesive solution A, on one surface of the polyester basematerial film, that has a width of 250 mm and a thickness of 25 μm, tohave the dried thickness of 10 μm, whereby the polyester releasing filmof 38 μm thickness was pasted on the surface. Then, the adhesive layeras the cleaning layer was provided by coating the above ultravioletcuring adhesive solution A on the other side of the base material filmto have the dried thickness of 10 μm, whereby the similar releasing filmwas pasted on the surface.

The cleaning sheet of the present invention was obtained by irradiatingthe ultraviolet rays having a central wavelength 365 nm until anintegrated quantity of light 1000 mJ/cm² onto this sheet. Then, thereleasing film on the cleaning layer side of this cleaning sheet waspeeled off, the coefficient of friction of the cleaning layer after theultraviolet rays curing was 1.7, and the modulus of elasticity intension of the cleaning layer after the ultraviolet curing was 50 N/mm².Here, the coefficient of friction was calculated by moving the stainlesssteel plate of 50 mm×50 mm under the vertical load 9.8 N at a velocityof 300 mm/min along the predetermined direction in parallel with thesurface of the cleaning layer, and then measuring the frictionalresistance force generated at that time by the universal tension tester.Also, the modulus of elasticity in tension was measured based on thetest method JIS K7127.

The conveying cleaning wafer with the cleaning function was fabricatedby peeling off the releasing film on the ordinary adhesive layer side ofthis cleaning sheet and then pasting the film on the back surface(non-cleaned surface) of the contact pin cleaner (product name Passchipmanufactured by PASS Co., Ltd.) as the contact pin cleaning member forthe 8-inch silicon wafer shape by the hand roller.

Then, when the cleaning of the contact pins and the cleaning of thechuck table were by peeling off the releasing film on the cleaning layerside of the cleaning member and then dummy-conveying through the waferprobe as the conduction testing device in the semiconductormanufacturing, the cleaning layer was not strongly brought into contactwith the contact portion at all and thus the cleaning layer could beconveyed without problem.

Also, when the contact pins were watched by the microscope thereafter,the foreign matters such as the oxide, etc. adhered to the pin beforethe cleaning were eliminated, and their cleaning can be checked. Also,the silicon waste having a size of about 1 mm, etc. appeared on thechuck table before the cleaning could be completely cleaned, and theircleaning could be found. Then, when 25 sheets of product wafers wereconveyed to perform the test actually, the process could be carried outnot to cause the problem.

EXAMPLE 7

The ultraviolet curing adhesive solution A was prepared by mixinguniformly the polyethylene glycol 200 dimethacrylate (product nameNKester4G manufactured by Shin-Nakamura Chemical Co., Ltd.) 50 parts,the urethane acrylate (product name U-N-01 manufactured by Shin-NakamuraChemical Co., Ltd.) 50 parts, and the polyisocyanate compound (productname Colonate L manufactured by Nippon Polyurethane Industry Co., Ltd.)3 parts, and the benzyldimethylketal (product name Illugacure 651manufactured by Chiba-Speciality Chemicals Co., Ltd.) 3 parts as thephotopolymerization initiator into the acrylic polymer (weight-averagemolecular weight 700000) 100 parts obtained from the monomer mixedsolution consisting of the acrylic acid-2-ethyl hexyl 75 parts, themethyl acrylate 20 parts, and the acrylic acid 5 parts.

In contrast, the normal pressure-sensitive adhesive solution A wasobtained in the same way as above except that the benzyldimethylketanolwas removed from the above adhesive.

The ordinary adhesive layer was provided by coating the abovepressure-sensitive adhesive solution A on one surface of the polyesterbase material film, that had a width of 250 mm and a thickness of 25 μm,to have a dried thickness of 10 μm, whereby the polyester releasing filmof 38 μm thickness was pasted on the surface. Also, the adhesive layerwas provided as the cleaning layer by coating the above ultravioletcuring adhesive solution A on the other side of the base material tohave the dried thickness of 30 μm, whereby the similar releasing filmwas pasted on the surface. Thus, the cleaning sheet A was fabricated.

When the modulus of elasticity in tension (test method JIS K7127) ofthis ultraviolet curing adhesive solution A was measured, 0.1 N/mm² wasobtained if the curing reaction was executed by the ultraviolet rays,while 49 N/mm² was obtained after the ultraviolet rays having thecentral wavelength 365 nm were irradiated up to the integrated quantityof light 1000 mJ/cm².

By using this cleaning sheet A, the sheet was pasted onto the wafer bythe direct cutting system tape sticker (NEL-DR8500II manufactured byNitto Seiki Co., Ltd.). At this time, the sheet A was pasted onto theback surface (mirror surface) of the 8-inch silicon wafer and then cutinto the wafer shape by the direct cut. When this operation for 25sheets was carried out successively, the cutting scobs were notgenerated at all in cutting the sheet.

Then, the conveying cleaning wafer A with the cleaning function wasfabricated by irradiating the ultraviolet rays having the centralwavelength 365 nm to five sheets of these wafers up to the integratedquantity of light 1000 mJ/cm².

In contrast, when the foreign matters having a size of more than 0.2 μmon the mirror surfaces of four sheets of new 8-inch silicon wafers werecounted by the laser foreign-matter measuring device, 8 foreign matterswere counted on the first sheet, 11 foreign matters were counted on thesecond sheet, 9 foreign matters were counted on the third sheet, and 5foreign matters were counted on the fourth sheet. When these wafers wereconveyed into the substrate processing equipment that has separateelectrostatic adsorbing mechanisms while directing the mirror surfacedownward and then the mirror surfaces were measured by the laserforeign-matter measuring equipment, 31254, 29954, 28683 and 27986foreign matters were counted in the first, second, third, and fourthareas of the 8-inch wafer size respectively.

Then, when the releasing film on the cleaning layer side of theresultant conveying cleaning wafer A was peeled off and then the waferwas conveyed into the substrate processing equipment that has the waferstage to which the above 31254 foreign matters were adhered, the wafercould be conveyed without trouble. Then, the new 8-inch silicon wafersto which the 10 foreign matters having the size of more than 0.2 μm wereconveyed while directing the mirror surface downward and then theforeign matters having the size of more than 0.2 μm were counted by thelaser foreign-matter measuring device. This operation was repeated fivetimes, and the results are shown in Table 3.

EXAMPLE 8

The cleaning sheet B was prepared in the same way as Example 7 exceptthat the ultraviolet curing adhesive solution B, that was obtained bymixing uniformly the multifunctional urethane acrylate (product nameUV1700B manufactured by The Nippon Synthetic Chemical Industry, Co.,Ltd.) 100 parts and the polyisocyanate compound (product name Colonate Lmanufactured by Nippon Polyurethane Industry Co., Ltd.) 3 parts, and thebenzyldimethylketal (product name Illugacure 651 manufactured byChiba-Speciality Chemicals Co., Ltd.) 10 parts as thephotopolymerization initiator into the acrylic polymer (weight-averagemolecular weight 2800000) 100 parts obtained from the monomer mixedsolution consisting of the acrylic acid-2-ethyl hexyl 75 parts, themethyl acrylate 20 parts, and the acrylic acid 5 parts, as theultraviolet curing adhesive. When the modulus of elasticity in tensionof this ultraviolet curing adhesive B was measured, 0.01 N/mm² wasobtained before the curing, while 1440 N/mm² was obtained after theultraviolet rays having the central wavelength 365 nm were irradiated upto the integrated quantity of light 1000 mJ/cm².

When 25 sheets of wafers with sheets were fabricated by the directcutting system using this cleaning sheet B like Example 7, the cuttingscobs were not generated at all in cutting the sheet. Then, theconveying cleaning wafer B with the cleaning function was fabricated byirradiating the ultraviolet rays having the central wavelength 365 nm tofive sheets of these wafers up to the integrated quantity of light 1000mJ/cm².

Then, when the releasing film on the cleaning layer side of theresultant conveying cleaning wafer A was peeled off and then the waferwas conveyed into the substrate processing equipment that has the waferstage to which the above 29954 foreign matters are adhered, the wafercould be conveyed without trouble. Then, the new 8-inch silicon wafersto which the 10 foreign matters having the size of more than 0.2 μm wereconveyed while directing the mirror surface downward and then theforeign matters having the size of more than 0.2 μm were counted by thelaser foreign-matter measuring device. This operation was repeated fivetimes, and the results are shown in Table 3.

Comparative Example 7

When the wafers with sheets were fabricated by the direct cutting systemsimilarly except that the cleaning sheet C was fabricated by irradiatingthe ultraviolet rays having the central wavelength 365 nm up to theintegrated quantity of light 1000 mJ/cm² before the wafer was pastedonto the cleaning sheet A in Example 7, a large amount of cutting scobswere generated from the cleaning layer in cutting the sheet. Thus, anumber of cutting scobs were stuck onto the edges of the wafers with thesheet, the back surface of the wafer, and the tape pasting device.Accordingly, the fabrication of the wafer C with the sheet wasinterrupted.

Comparative Example 8

The cleaning sheet D was fabricated in the same way as Example 7 exceptthat the pressure-sensitive adhesive solution A shown in Example 8 wasemployed as the adhesive for the cleaning layer. In this case, themodulus of elasticity in tension of the cleaning layer was 0.1 N/mm².

When the wafers with sheets were fabricated by the direct cutting systemin the same way as Example 7 from the cleaning sheet D, no cutting scobwas generated in cutting the sheet and thus 25-sheets of wafers could befabricated. When these conveying cleaning wafers D were conveyed intothe substrate processing equipment that has the wafer stage to which the27986 foreign matters were adhered, the first wafer wais stuck to thewafer stage and thus could not be conveyed.

TABLE 3 Foreign-matter rejection ratio 1 sheet 2 sheets 3 sheets 4sheets 5 sheets conveyed conveyed conveyed conveyed conveyed Example 785% 92% 96% 96% 96% Example 8 70% 75% 83% 83% 83% Comparative(manufacturing of the cleaning wafer was stopped) Example 7 Comparativeconveyance conveyance conveyance conveyance conveyance Example 8 troubleoccurred stopped stopped stopped stopped

Industrial Applicability

As described above, according to the cleaning sheet of the presentinvention, the substrate can be conveyed in the substrate processingequipment without fail and also the foreign matters adhered onto theequipment can be simply reduced.

Although the invention has been described in its preferred form with acertain degree of particularity, it is understood that the presentdisclosure of the preferred form can be changed in the details ofconstruction and in the combination and arrangement of parts withoutdeparting from the spirit and the scope of the invention as hereinafterclaimed.

What is claimed is:
 1. A cleaning sheet comprising a cleaning layerhaving a surface resistivity more than 1×10¹³ Ω/□.
 2. A cleaning sheetset forth in claim 1, further comprising a base material for supportingsaid cleaning layer.
 3. A cleaning sheet set forth in claim 1, furthercomprising: a base material having one surface on which said cleaninglayer is provide; and an adhesive layer being on an other surface ofsaid base material.
 4. A cleaning sheet according to claim 1, wherein arelative dielectric constant of the cleaning layer is larger than 2.0.5. A cleaning sheet according to claim 1, wherein a surface free energyof the cleaning layer is not less than 30 mJ/m².
 6. A cleaning sheetaccording to claim 5, wherein a contact angle with respect to water ofthe cleaning layer is not more than 90 degrees.
 7. A cleaning sheetaccording to claim 1, wherein a surface potential of the cleaning layerexceeds 10 kV.
 8. A cleaning sheer according to claim 7, wherein thecleaning layer is formed as an electret by a thermal electret method. 9.A cleaning sheet according to claim 1, wherein the cleaning layer doesnot substantially have a tackiness.
 10. A cleaning sheet according toclaim 1, wherein a modulus of elasticity in tension according to testmethod JIS K7127 of the cleaning layer is 1 to 3000 N/mm².
 11. Acleaning sheet according to claim 1, wherein the cleaning layer isformed of an adhesive layer that is cured by an active energy.
 12. Aconveying member with a cleaning function in which the cleaning sheetset forth in claim 3 is provided to a conveying member via an adhesivelayer.
 13. A substrate processing equipment cleaning method of conveyingthe cleaning sheet set forth in claim 1 or the conveying member setforth in claim 12 into a substrate processing equipment.
 14. A cleaningmember which is a cleaning member for a conduction testing equipment andin which the cleaning sheet set forth in claim 1 for removing foreignmatters adhered onto a contacted surface of the equipment, with which acontact pin cleaner comes into contact, is provided to one surface of amember for removing foreign matters adhered to a conduction testingcontact pin of the equipment.
 15. A cleaning member which is a cleaningmember for a conduction testing equipment and in which a contact pincleaner for removing foreign matters adhered onto a conduction testingcontact pin of the equipment is provided to one surface of a conveyingmember, and the cleaning sheet set forth in claim 1 for removing theforeign matters adhered to a contacted surface of the equipment, withwhich the contact pin cleaner comes into contact, is provided to another surface of the conveying member.
 16. A cleaning member accordingto any one of claims 14 and 15, wherein, in the cleaning sheet, anadhesive layer is provided onto one surface of a base material and acleaning layer for removing the foreign matters adhered to the contactedsurface of the equipment, with which the contact pin cleaner comes intocontact, is provided onto an other surface of the base material.
 17. Acleaning sheet according to claim 1, wherein a coefficient of frictionof the cleaning layer is not less than 1.0.
 18. A cleaning sheetaccording to claim 1, wherein the adhesive layer is a curing adhesivethat contains a pressure-sensitive adhesive polymer, a polymerizedunsaturated compound that has one upsaturated double bond or more in amolecule, and a polymerization initiator.
 19. A conduction testercleaning method of conveying the cleaning member set forth in any one ofclaims 14 and 15 into a conduction tester.